Density functional theory quantum chemical calculations corrected with empirical atomic increments have been used to determine the gas-phase standard enthalpy of formation at 298.15 K of more than 80 oxygenated radicals potentially formed during thermal decomposition and oxidation of fatty acid methyl esters (FAMEs) at combustion temperatures. Neither experimental nor theoretical data have been found in the literature for these radicals. C−H and C−C bond scissions in FAMEs are examined and mechanistic information is obtained based on thermochemical considerations.